This invention relates to a unique high moisture pet food product which is preserved against bacterial and mycotic spoilage and a process for producing the same.
The pet food market has in recent times become segmented into three major categories based on the moisture content of the pet food. These being (1) dry pet foods or those having a moisture content generally below about 15% by weight, (2) intermediate or soft moist pet foods which have a moisture content generally of between 15 and 35% by weight, and (3) high moisture pet foods or those having a moisture content which exceed about 40% by weight. While commercial products in all of these categories have been quite successful, the dry and intermediate moisture pet foods have the distinct advantage over high moisture pet foods of being convenient to use by the consumer, and therefore, easy to feed to the animal. This advantage is provided in the case of dry foods, by the relatively low moisture content which does not require expensive packaging or special preservatives for storage of the product under ambient conditions. Intermediate moisture pet foods, on the other hand, are equally convenient but require the use of preservatives or special packaging since the moisture content is sufficient to support bacterial and mold growth. Both of these products, however, suffer the disadvantage over high moisture products of not being generally as palatable to the pet. Therefore, in spite of the tremendous advantages with regard to convenience that dry and intermediate moisture pet foods have to offer, they still have as a general deficiency, a somewhat lower level of acceptance by the animal as compared to the high moisture products.
As is apparent, however, the high moisture products, in spite of being more palatable, suffer from the need for expensive packaging and processes employing sterilization because the high moisture level provides a virulent media for the growth of microorganisms. High moisture pet foods of the prior art has heretofore been limited to a single type of product which is packaged in a can and has been cooked and sterilized to provide the product with an acceptable shelf life. On the other hand, after the product is opened, it rapidly spoils without refrigeration, and apportioned feeding of the product to the pet is very difficult. A need has, therefore, been recognized for a high moisture pet food product which has the palatability of the canned products with the storage and packaging requirements of a dry or intermediate moisture product, but with the aesthetic appeal of a cooked piece of meat.
Intermediate moisture pet foods which have a lower moisture content of between about 15 to 35% by weight generally have been dependent on a reduction in the water activity of the product to prevent substantial bacterial growth. The addition of an antimycotic has also been required to inhibit mold growth. Typical intermediate moisture pet foods having a reduced water activity are disclosed in U.S. Pat. Nos. 3,202,514, 3,482,985, 3,615,652 and 3,653,908. These have generally involved the addition of water soluble solids such as sugar or reduced polysaccharides to reduce the water activity to an acceptable level to prevent bacterial propagation. Sugar and water soluble solids of this type are, however, entirely unusable in stabilizing high moisture pet foods since they cannot reduce the water activity to a low enough level to prevent bacterial growth to any extent.
Aside from the problems of preservation associated with high moisture pet foods, aesthetic appeal of the product is also extremely important assuming it is preserved against bacterial and mycotic penetration, since the mushy appearing mixture of meat and cereal grains normally associated with canned products is not the most appealing and convenient to feed. In this respect, the intermediate moisture products have a coherent nature, yet are soft and moist in texture to a sufficient degree to have a desirable appearance, and therefore have a high degree of aesthetic appeal to the consumer. It would, therefore, be highly desirable to provide a high moisture pet food which is bacteriologically stable and can be easily packaged and stored under ambient conditions, yet have the aesthetic appeal and convenience of an intermediate moisture pet food.
The present invention, therefore, provides a solution to this need by providing a unique high moisture pet food which by appearance resembles a freshly cooked "patty" of hamburger yet is completely preserved against bacterial and mycotic penetration. Furthermore, this product is formed by a process which gives the product maximum aesthetic appeal, in that it can be broken apart by hand for apportioned feeding to the pet and upon breaking, has a "chunky" meat appearance rather than the mushy homogeneous, appearance one would expect from combining the diverse ingredients of the present invention including cooked meat, water and preservative. This desirable chunky appearance is characterized by the product having a shear value above about .080 ft. lb./gram as compared to a mushy homogeneous ground product of nearly identical ingredients which has a shear value below this.